The present invention relates to a touch input device.
In the prior art, a display system including a touch input device and a display has been proposed (e.g., Japanese Laid-Open Patent Publication No. 2001-325072). The display system may be used in, for example, a vehicle. In such a display system, the touch input device is arranged where it can easily be operated such as on the center console. The display is arranged where it can easily be viewed such as on a center cluster panel. A user touches an operation plane of the touch input device to select one of a plurality of function items shown on a display. This enables the desired screen to be shown on the display or the corresponding vehicle equipment to be operated.
There are two types of touch operations performed by a user when touching such a touch input device. One is a trace operation in which the user traces the operation plane of the touch input device. That is, the user moves his or her finger along the operation plane to reach a desired function item shown on the display. Another is a selection operation in which the user presses the operation plane to select a function item. The user performs the trace operation to locate the desired function item shown on the display. Then, the user performs the selection operation to select that function item.
FIG. 7 shows the structure of a typical touch input device 100 that undergoes such trace and touch operations. The touch input device 100 includes an operation plane 101, a pivotal member 102, and a tactile switch 103. The pivotal member 102 is pivotal about fulcrum O when the operation plane 101 is pressed. In other words, the touch input device 100 has a hinged mechanism. When the user presses the operation plane 101 to perform a selection operation, the pivotal member 102 is pivoted to the state shown by broken lines in FIG. 7 so as to activate the tactile switch 103. This selects a function item shown on the display. In the touch input device 100, the hinged mechanism prevents the operation plane from swaying when the trace operation and selection operation are performed. This improves the feel of the operation plane 101 when the operation plane 101 is touched.
There is now a demand for smaller touch input devices. However, the touch input device 100 of the prior art employs the hinged mechanism to enable the selection operation. Therefore, the structure of the touch input device 100 is complicated and causes miniaturization to be difficult. Especially because of the pivoting of the pivotal member 102, space is required in a direction orthogonal to the operation plane 101. This hinders miniaturization of the touch input device 100. Accordingly, there is a demand for a touch input device having a simplified structure that can be miniaturized.